Long Beach, California—TED convened in Long Beach this morning, and in the beginning, there was science. Dubbed The Observatory, Session 1 was about how we look at our world and choose to engage it.

"Gazing out at the stars is the best way I know to evoke wonder," Chris Anderson, TED’s curator, opined. But just what are we looking at?

Brian Greene told the audience at TED that the wonder we see is not only mysterious, but a limited-run engagement. Greene is a theoretical physicist who has been engaging the public through books, PBS specials, and by organizing the World Science Festival. Here, Greene was in cosmologist mode, talking about how the Universe is going to change in ways that will fundamentally alter how it can be observed.

Astronomers in the far future will not have the beautiful night sky we have. In fact, unless they have our knowledge and scientific records, they will think that the Universe is a dark, static and unchanging place. Why will our night sky go black? The expansion of our Universe will eventually push other galaxies so far from us that we will no longer see them, even with advanced equipment. Light cannot overcome all distances, Greene said, describing a future where all we can see are the galaxies in our immediate neighborhood.

(In this part of his talk, Greene was expressing ideas similar ideas to those explored in detail by Lawrence Krauss, who has published papers on how the Universe will destroy evidence of its past. We'll have more thoughts from Krauss later this week via a review of his latest book.)

But that future is still billions of years off, and in the meantime, there's a lot to learn. "We are living through a remarkably privileged era," notes Greene. "Deep truths about the cosmos are still within reach."

And there’s a chance that, in the future, we might see something truly astonishing: proof that our Universe has collided with another universe. Some theoretical ideas on the origin of our Universe suggest it was just one of many that could form, all expanding from an inflationary fabric. Greene presents an even more intriguing idea: we may find that our universe is not the only universe but is instead part of a vast complex of universes that we call the multiverse."

It’s a strange concept. After all, "Universe" is supposed to mean everything, right? Whatever the word means, the reality is that the Universe surprises us at nearly every turn. It was only in 1929 that Hubble realized that space was expanding. Looking into the red shift, our beliefs about the Universe changed utterly. We grudgingly accepted this, but then slotted it into a new hypothesis: gravity is surely slowing its expansion down.

Of course, last year's Nobel Prize in Physics went to folks who found that not only is the Universe expanding, but its expansion is accelerating due to dark energy. The physics community has scrambled to try to find an explanation for dark energy, from returning to Einstein's cosmological constant to radical ideas coming out of string theory.

String theory posits that the four dimensions of the Universe that we experience only account for about a third of the actual dimensions, most of which remain balled up at distances far too small to be measured. The vibrations of these strings produce the fundamental particles—the electrons and quarks—that produce the visible matter in our Universe. With the right formulation, string theory unifies gravity and quantum mechanics, and produces a value for dark energy that fits nicely with the Universe we've observed.

There's just one problem: the odds of having the right formulation are vanishingly small. Green said that there are 10500 possible configurations of the extra dimensions, and only a tiny fraction of that number will produce anything that looks like our Universe. In this scenario, explaining dark energy becomes a different kind of problem. It's not how much dark energy is in our Universe—the question becomes one of why we have a particular amount of dark energy rather than any of the other possible amounts.

Why does our Universe have just the right conditions to support matter? Here, Greene made an analogy to Earth, asking why it is 93 million miles from the Sun, where water is mostly liquid. Is there some feature of the Universe that explains this? Or is this the wrong reasoning? It is, of course, the reasoning that's wrong. The right answer is that we find ourselves on Earth because Earth is hospitable to life.

We can think of our Universe in the same way. If dark energy can take on different values, it doesn’t make sense to ask what law generated this particular number. And, if the physics works out so that there is a multiverse, then we can conclude we're in one compatible with life because we wouldn't be here to contemplate the question otherwise.

Greene indicated that this is actually a scientific idea, in that it's testable. "Could we ever confirm the existence of other universes?" Green asked, before answering in the affirmative. It may be possible for us to see the effects of a collision with another universe by examining the cosmic microwave background left over from early in our own Universe's history. If our Universe isn't an only child, there's a chance one of its siblings left an imprint.

We have a few billion years before the Universe erases that evidence, so we continue to watch the sky until then.

Update: an earlier version of this article implied that Greene discussed the Multiverse in factual terms when he did not. Rather, Greene was discussing a fascinating but also controversial and theoretical framework for understanding the dark energy in our universe.

Ken Fisher
Ken is the founder & Editor-in-Chief of Ars Technica. A veteran of the IT industry and a scholar of antiquity, Ken studies the emergence of intellectual property regimes and their effects on culture and innovation. Emailken@arstechnica.com//Twitter@kenfisher

Invoking the anthropic principle is considered (by me mainly) poor form for a real cosmologist. It would get you laughed/chided out of any serious conference, and possibly even a grad/undergrad class. Mr Greene has balls of red matter apparently. I guess it was just a Ted talk though.

Greene indicated that this is actually a scientific idea, in that it's testable. "Could we ever confirm the existence of other universes?" Green asked, before answering in the affirmative. It may be possible for us to see the effects of a collision with another universe by examining the cosmic microwave background left over from early in our own Universe's history. If our Universe isn't an only child, there's a chance one of its siblings left an imprint.

I remember an article (probably on ars) about a search for circular patterns in the microwave background radiation that were supposed to be the result of our universe colliding with another universe. There were no solid results.

Come to think of it, is not Sailor Moon in the Multiverse? If so, finding her would prove it's existence, would it not?

There are quite a few creative science fiction writers out there who pass themselves off as scientists. Basic scientific principles dictate that you should have some evidence before you get behind a hypothesis. Reasoning that involves the lack of a disproving theory is just bad logic.

You could have just gone with "Nothing of importance happened at TED. Nothing to see here, move along."

A bunch of what if's and possibilities sounds more like a religious conference than a science conference. Speculating on whether or not galaxies will be seen by future scientists is absolutely ridiculous, I would expect scientists would have better things to do.

There are quite a few creative science fiction writers out there who pass themselves off as scientists. Basic scientific principles dictate that you should have some evidence before you get behind a hypothesis. Reasoning that involves the lack of a disproving theory is just bad logic.

That's not really true at all. Sometimes very unrealistic theories are healthy for science: a) because they might be right, and b) because they can offer insights into more realistic theories that may otherwise be absent.

The only absolute truth in modern science is that we don't really "know" much of anything - what we know most likely amounts to a drop of water in the ocean. And any scientist who says that anything at all is utterly impossible is, in my book, not worth believing. Too many times have well-revered scientists with well-reviewed work been disproved years or decades after their time.

You could have just gone with "Nothing of importance happened at TED. Nothing to see here, move along."

A bunch of what if's and possibilities sounds more like a religious conference than a science conference. Speculating on whether or not galaxies will be seen by future scientists is absolutely ridiculous, I would expect scientists would have better things to do.

I could easily just add this quote to my post above, but would rather take this opportunity to add that rigid science very rarely progresses. If you only accept what you expect, then why are you bothering to be in science to begin with. the point of science, in my book, is discovery and exploration, not reiteration and acceptance.

You could have just gone with "Nothing of importance happened at TED. Nothing to see here, move along."

A bunch of what if's and possibilities sounds more like a religious conference than a science conference. Speculating on whether or not galaxies will be seen by future scientists is absolutely ridiculous, I would expect scientists would have better things to do.

There are scientists working on concrete problems, such as what gravity is, whether the Higgs boson really exists, dark energy, etc. I can understand the visceral reaction to the idea that these magic values are just coincidence. But mathematics has always sort of been sort of a scout ahead for physics, and the math appears to lead that way. That's no proof, of course, but categorizing this as pure speculation bordering on religion isn't at all the correct characterization.

It may not be hard science, yet, but that doesn't mean it doesn't merit thought and discussion in the scientific community.

There are quite a few creative science fiction writers out there who pass themselves off as scientists. Basic scientific principles dictate that you should have some evidence before you get behind a hypothesis. Reasoning that involves the lack of a disproving theory is just bad logic.

That's not really true at all. Sometimes very unrealistic theories are healthy for science: a) because they might be right, and b) because they can offer insights into more realistic theories that may otherwise be absent.

The only absolute truth in modern science is that we don't really "know" much of anything - what we know most likely amounts to a drop of water in the ocean. And any scientist who says that anything at all is utterly impossible is, in my book, not worth believing. Too many times have well-revered scientists with well-reviewed work been disproved years or decades after their time.

I agree that thinking outside the box is a good thing.. Its another to completely indulge in fantasy that has no supportive evidence.

By your logic, maybe we should teach the creation myths in the classroom as well. Who knows, they might be right.

Scientists should feel free to challenge accepted norms, pose questions they feel need answers, and criticize any assertions they feel are weakly grounded. Just fabricating ideas that are not based on any evidence ISN'T science. Its philosophy. While I'd be the first person to endorse the value of philosophy, and its potential merits for opening up our minds... I'll also be the first to tell you that its not science.

That is my current gripe with the scientific community.. specifically fields like cosmology. I know its hard to gather evidence when you are stuck millions of miles away, but you still need evidence to support hypothesis. If its not testable, or you can't prove it, its not science.

You could have just gone with "Nothing of importance happened at TED. Nothing to see here, move along."

A bunch of what if's and possibilities sounds more like a religious conference than a science conference. Speculating on whether or not galaxies will be seen by future scientists is absolutely ridiculous, I would expect scientists would have better things to do.

Every inventor who ever lived would like to have a word with you.

Specifically discussing what scientists will be doing when the universe has changed so much that galaxies we see now are no longer in view, is, I would venture further thinking out then any inventor EVER. Furthermore, there was nothing mentioned about actual inventions that are going to do anything and that best it was something we could test but in our current capacities there would be no outcome that would likely point to a multiverse. Go for it, test all you want. For as much as he accomplished in all those what-if's I could have showed up and said, "thousands of years in the future, there will be travel by stargates" and it would have been equally as useful.

I agree that thinking outside the box is a good thing.. Its another to completely indulge in fantasy that has no supportive evidence.

By your logic, maybe we should teach the creation myths in the classroom as well. Who knows, they might be right.

Teaching is not the same as researching. TED conferences are, in some ways educational. They are not, however, indoctrinating the same way that primary and secondary education are.

Quote:

Scientists should feel free to challenge accepted norms, pose questions they feel need answers, and criticize any assertions they feel are weakly grounded. Just fabricating ideas that are not based on any evidence ISN'T science. Its philosophy. While I'd be the first person to endorse the value of philosophy, and its potential merits for opening up our minds... I'll also be the first to tell you that its not science.

I think there's a fine line there. There's a reason that you can get an M.S. in Physics (Master of Science), but not a S.D. in Physics (rather a Ph.D. - Doctor of Philosophy). Philosophy of a chosen art, scientific or otherwise, is considered by many in the academic world, at least (and surely elsewhere) to be of the highest possible value. Mastering what is is significant for using what we know. Philosophizing on science, however, is the only way large leaps of progress occur.

It's not how much dark energy is in our Universe—the question becomes one of why we have a particular amount of dark energy rather than any of the other possible amounts.

Because a creator was involved.

*makes a run for it*

Why run? I'm sitting here laughing at all this because that's exactly what they're proving by asking the question of why things are in such ultra-precise arrangements. That doesn't simply happen by chance.

You could have just gone with "Nothing of importance happened at TED. Nothing to see here, move along."

A bunch of what if's and possibilities sounds more like a religious conference than a science conference. Speculating on whether or not galaxies will be seen by future scientists is absolutely ridiculous, I would expect scientists would have better things to do.

I could easily just add this quote to my post above, but would rather take this opportunity to add that rigid science very rarely progresses. If you only accept what you expect, then why are you bothering to be in science to begin with. the point of science, in my book, is discovery and exploration, not reiteration and acceptance.

I don't have any expectations that I would solely accept over theories of a multiverse right off the top of my head. I wasn't driven to say speculation in general is bad, I'm saying thinking too far out has it's disadvantages as well. We've barely brushed the surface of current issues to even think that humanity would survive to see the day our current view of the stars is significantly altered. I know that's not the entire article's summarization, but should we focus on finding proof of something as intangible as another universe before we can, say, find a cure for a tangible disease or affliction that permeates our current universe?

I think you might be getting an idea of me being close-minded to scientific progression merely on the basis I said its a waste of time to think scientists of the future will even be concerned about how many universal truths are able to be divulged simply because the same stars won't be in the same place. I would hope that in that distant of a future, something like location of stars wouldn't be able to hold science from gleaning their secrets.

That is my current gripe with the scientific community.. specifically fields like cosmology. I know its hard to gather evidence when you are stuck millions of miles away, but you still need evidence to support hypothesis. If its not testable, or you can't prove it, its not science.

Actually, many cosmologists would say that they are in a golden age in terms of raw data provided them by astronomers. There is an ungodly amount of data that needs to be looked at (e.g. SDSS will have surveyed something like 1/2 a billion objects by the time it is done, and that is just one survey). There is WMAP data that is totally awesome. They are probing higher and higher red shifts, etc, etc. I am not necessarily disagreeing with the idea that people should not make testable claims, but I don't think scientists in general do this. Ever. Cosmologists definitely don't do it in real research/literature. Well, not any that have any level of credibility in their field at least.

Invoking the anthropic principle is considered (by me mainly) poor form for a real cosmologist. It would get you laughed/chided out of any serious conference, and possibly even a grad/undergrad class. Mr Greene has balls of red matter apparently. I guess it was just a Ted talk though.

Got a better idea for why the universe is so absurdly well balanced as to provide a place where life could develop?

nicknomo:

Quote:

That is my current gripe with the scientific community.. specifically fields like cosmology. I know its hard to gather evidence when you are stuck millions of miles away, but you still need evidence to support hypothesis. If its not testable, or you can't prove it, its not science.

There is a big difference between something that isn't testable right now and something that cannot ever be tested. Greene's ideas fall in the first group, religion is in the second. There is nothing wrong with exploring theories that cannot be experimentally verified right now and part of the difficulty with something like string theory is understanding it well enough to make predictions that can be tested. Until people can get their heads round it, there isn't going to be much that they can ask the experimental scientists to look for.

It's not how much dark energy is in our Universe—the question becomes one of why we have a particular amount of dark energy rather than any of the other possible amounts.

Because a creator was involved.

*makes a run for it*

Why run? I'm sitting here laughing at all this because that's exactly what they're proving by asking the question of why things are in such ultra-precise arrangements. That doesn't simply happen by chance.

Or maybe if, as you put it, things weren't in such ultra precise arrangement, you wouldn't exist to laugh about why things are in such precise arrangement.

There is a big difference between something that isn't testable right now and something that cannot ever be tested. Greene's ideas fall in the first group, religion is in the second. There is nothing wrong with exploring theories that cannot be experimentally verified right now and part of the difficulty with something like string theory is understanding it well enough to make predictions that can be tested. Until people can get their heads round it, there isn't going to be much that they can ask the experimental scientists to look for.

In all fairness (and from a strictly scientific perspective), it's impossible to say that religion may not be testable in the future.

a) If, in fact, Christianity is correct, it will be verifiable after mortal life ends for each of us.

b) If, in fact, any of it is at all correct, it's possible that science may be able to detect "god-particles" or "spirits" or any other manner of thing. People have known since the existence of people that their feet stayed on the ground - they couldn't measure gravity until pretty recently.

Greene indicated that this is actually a scientific idea, in that it's testable. "Could we ever confirm the existence of other universes?" Green asked, before answering in the affirmative. It may be possible for us to see the effects of a collision with another universe by examining the cosmic microwave background left over from early in our own Universe's history. If our Universe isn't an only child, there's a chance one of its siblings left an imprint.

That's not enough. To pass for a scientific theory, this idea must be falsifiable; there must be tests that can disprove it. I haven't heard anyone suggest any way disprove the multiverse idea, just ideas of how it might be detected if it was real. The same is true of Leprechauns.

Lately I find myself so annoyed that folks like Greene state these ideas as facts, rather than the cool ideas that they are, that I have a harder and harder time getting excited about them like I did in the past.

I think there's a fine line there. There's a reason that you can get an M.S. in Physics (Master of Science), but not a S.D. in Physics (rather a Ph.D. - Doctor of Philosophy). Philosophy of a chosen art, scientific or otherwise, is considered by many in the academic world, at least (and surely elsewhere) to be of the highest possible value. Mastering what is is significant for using what we know. Philosophizing on science, however, is the only way large leaps of progress occur.

Invoking the anthropic principle is considered (by me mainly) poor form for a real cosmologist. It would get you laughed/chided out of any serious conference, and possibly even a grad/undergrad class. Mr Greene has balls of red matter apparently. I guess it was just a Ted talk though.

Got a better idea for why the universe is so absurdly well balanced as to provide a place where life could develop?

No, not yet. But that isn't to say that there couldn't be a physical reason as to why the distribution is exactly the way it is. It is an important distinction.

A number of cosmologists have already weighed in on the anthropic principle and essentially say things like, "it tends to be invoked by theorists whenever they do not have a good enough theory to explain the observed facts," (quote from Penrose).

Quote:

There is a big difference between something that isn't testable right now and something that cannot ever be tested. Greene's ideas fall in the first group, religion is in the second. There is nothing wrong with exploring theories that cannot be experimentally verified right now and part of the difficulty with something like string theory is understanding it well enough to make predictions that can be tested. Until people can get their heads round it, there isn't going to be much that they can ask the experimental scientists to look for.

Well, string theory doesn't really make a 'prediction' in the traditional sense. It in fact makes, as was summarized in the article, something like 10^500 predictions with no indication or weight given to which is actually correct. The anthropic principle can be used to tune the values of your preferred flavor of string theory, but it's kind of unscientific way to do it. Recently a lot of the support that string theory used to garner is actually falling away. It's not a particularly healthy field right now to be in because it is not predictive, and little theory has come along recently (that I am aware of) that significantly alters this. It's a supremely elegant bit of mathematics, and appeals to physicists because of it's relatively limited assumptions and 'simplicity' - but that doesn't make it right.

Aside: currently reading Iain Bank's Transition, a novel featuring a 'multiverse' situation. Banks posits that the logical meaning is that the universe splits everytime anything happens, be it a photon taking a particular path, or a radioactive particle decaying.

I can't do the calculation.

If 'every possible path' IS taken for every possible particle, and each of those paths invokes a completely separate universe, each of those universes splitting in the same way, it's an infinity of infinities, infinitely expanding at an infinitely accelerating rate.

A planck-second is a time unit, which is the time taken for a photon at c to cross a planck length. It's a very small unit of time. The quickest measured event we can measure is about 12 attoseconds (12*10^-18 seconds). A planck second is about 5*10^-44seconds. Thats billions upon billions upon billions upon billions of times 'less time' than the chunks we can accurately measure.

If every planck second the entire ~10^100 particles of the observable universe hives off into 10^100 possible configurations, and each of those hived off universes follows suit ... the calculation defies my primitive grasp of mathematics.

That is my current gripe with the scientific community.. specifically fields like cosmology. I know its hard to gather evidence when you are stuck millions of miles away, but you still need evidence to support hypothesis. If its not testable, or you can't prove it, its not science.

Yes, you would've said the same thing to Albert Einstein in 1905. It's easy to dismiss theories because they are just that: theories. Even so, it's not impossible, but just not the right time or the right technological level to come up with some kind of experiment to test.

it's an infinity of infinities, infinitely expanding at an infinitely accelerating rate.

...the calculation defies my primitive grasp of mathematics.

Just remember, infinity is not a number, its a concept. You cant have infinity to the infinity'ith power. Just thought Id point that out to spare your greymatter spontaneous combustion. =D

Since there are (or would be if multiverse was true) an infinite number of universes, even the most unlikely statistical anomalies are guaranteed to occur an infinite number of times. Of course, thats if you believe this version of metaphysics...

Aside: currently reading Iain Bank's Transition, a novel featuring a 'multiverse' situation. Banks posits that the logical meaning is that the universe splits everytime anything happens, be it a photon taking a particular path, or a radioactive particle decaying.

I can't do the calculation.

If 'every possible path' IS taken for every possible particle, and each of those paths invokes a completely separate universe, each of those universes splitting in the same way, it's an infinity of infinities, infinitely expanding at an infinitely accelerating rate.

A planck-second is a time unit, which is the time taken for a photon at c to cross a planck length. It's a very small unit of time. The quickest measured event we can measure is about 12 attoseconds (12*10^-18 seconds). A planck second is about 5*10^-44seconds. Thats billions upon billions upon billions upon billions of times 'less time' than the chunks we can accurately measure.

If every planck second the entire ~10^100 particles of the observable universe hives off into 10^100 possible configurations, and each of those hived off universes follows suit ... the calculation defies my primitive grasp of mathematics.

So yeah, multiverse is a pretty whacked theory.

Please stop getting your science from fiction.

Multiverses theory is not linked to the decades-old SciFi concepts of parallel universes where everything that can occur has occurred. A photon taking a different path is not what spawns another universe in the multiverse theory. There will not be 285,000 Enterprises all hailing each other.

Second, planck's constant is a factor in this universe. It may not apply to a multiverse. We have no physics to describe the multiverse, or anything outside our own universe.

Remember. The thing you thought of in the first 5 minutes? People who spent a lifetime doing this? They thought of it too.

Personally I think the multiverse idea is bogus. But it apparently is testable, so let's wait and see. We will know soon enough. CMB mapping missions more accurate than WMAP are in the works. When we get more accurate data we may see ring-like patterns. Or not. Then we'll know.

<quote>It may be possible for us to see the effects of a collision with another universe by examining the cosmic microwave background left over from early in our own Universe's history. If our Universe isn't an only child, there's a chance one of its siblings left an imprint.</quote>

Invoking the anthropic principle is considered (by me mainly) poor form for a real cosmologist. It would get you laughed/chided out of any serious conference, and possibly even a grad/undergrad class. Mr Greene has balls of red matter apparently. I guess it was just a Ted talk though.

You have my vote. Glad to see at least one other person agrees on the absurdity of this causality-reversing "explanation".

"Hey, did you hear that Mike at the office won the lottery ten times in a row? How do you think -that- happened?"

"Well, it's quite simple, actually. If he hadn't won the lottery ten times in a row, we wouldn't be here talking about how he won ten times in a row."

There are quite a few creative science fiction writers out there who pass themselves off as scientists. Basic scientific principles dictate that you should have some evidence before you get behind a hypothesis. Reasoning that involves the lack of a disproving theory is just bad logic.

That's not really true at all. Sometimes very unrealistic theories are healthy for science: a) because they might be right, and b) because they can offer insights into more realistic theories that may otherwise be absent.

The only absolute truth in modern science is that we don't really "know" much of anything - what we know most likely amounts to a drop of water in the ocean. And any scientist who says that anything at all is utterly impossible is, in my book, not worth believing. Too many times have well-revered scientists with well-reviewed work been disproved years or decades after their time.

Someone smart once said, the more I learn the more I realize how little I know. The real truth about unrealistic theories is that the majority of scientists are not willing to voice their crazy ideas until they have tested them a little. Captainpuke described Mr. Greene's gonads appropriately.

As for well-revered scientists being disproved, that actually happens very little. Much more often their theory is used as a spring board to new theories and/or modified to find a more accurate understanding, but rarely is their whole work thrown out. As to become well-revered you have to have good science to back up your theories and good science is repeatable by others.

On another note: I wonder how future civilizations will describe the origin of the universe when the skies are black, and does anyone else wonder if we could also be missing some critical observable information that has passed away, which if we could see it would completely change our understanding?

It's not how much dark energy is in our Universe—the question becomes one of why we have a particular amount of dark energy rather than any of the other possible amounts.

Because a creator was involved.

*makes a run for it*

Why run? I'm sitting here laughing at all this because that's exactly what they're proving by asking the question of why things are in such ultra-precise arrangements. That doesn't simply happen by chance.

It doesn't prove any such thing. Like many, you seem to back yourself into a false dichotomy; where if one thing isn't true, then the other thing must be. No, the universe didn't simply happen by chance; there's going to be science behind it. Because of course, the universe is perfect.

Now, one reason we know it's perfect, (and perhaps the only one we have at hand at the moment) is that if it wasn't perfect, we wouldn't be here to observe it. But just because the one fact is a prerequisite of the other, does not mean that that fact is the cause of the other. Science is looking for the causes of truth, whereas it's philosophy and theology that attempt to take the causal, along with the results, in an attempt to provide insight to the truth as a whole. While that's great, and surely a worthy addition to the human condition; it's not testable or verifiable; and thus, not science.

A thinking man does himself no favors when he conflates the two. I think you come from the theological, in an attempt to arrive at science; and I think this Greene fellow comes from the discipline of science, and somehow arrives, if not at a theological result; at least a philosophical one. His hypotheses are not testable or verifiable; well, beyond "here's what my crazy math says when taken to illogical extremes"..

Aside: currently reading Iain Bank's Transition, a novel featuring a 'multiverse' situation. Banks posits that the logical meaning is that the universe splits everytime anything happens, be it a photon taking a particular path, or a radioactive particle decaying.

I can't do the calculation.

If 'every possible path' IS taken for every possible particle, and each of those paths invokes a completely separate universe, each of those universes splitting in the same way, it's an infinity of infinities, infinitely expanding at an infinitely accelerating rate.

A planck-second is a time unit, which is the time taken for a photon at c to cross a planck length. It's a very small unit of time. The quickest measured event we can measure is about 12 attoseconds (12*10^-18 seconds). A planck second is about 5*10^-44seconds. Thats billions upon billions upon billions upon billions of times 'less time' than the chunks we can accurately measure.

If every planck second the entire ~10^100 particles of the observable universe hives off into 10^100 possible configurations, and each of those hived off universes follows suit ... the calculation defies my primitive grasp of mathematics.

So yeah, multiverse is a pretty whacked theory.

Please stop getting your science from fiction.

Multiverses theory is not linked to the decades-old SciFi concepts of parallel universes where everything that can occur has occurred. A photon taking a different path is not what spawns another universe in the multiverse theory. There will not be 285,000 Enterprises all hailing each other.

Second, planck's constant is a factor in this universe. It may not apply to a multiverse. We have no physics to describe the multiverse, or anything outside our own universe.

Remember. The thing you thought of in the first 5 minutes? People who spent a lifetime doing this? They thought of it too.

Personally I think the multiverse idea is bogus. But it apparently is testable, so let's wait and see. We will know soon enough. CMB mapping missions more accurate than WMAP are in the works. When we get more accurate data we may see ring-like patterns. Or not. Then we'll know.

Actually, the scenario Excession describes is exactly how Greene describes the multiverse, so I would say your understanding is incorrect. This episode of Radiolab includes an interview with him (Greene, not Excession ) in which he describes the concept and some of the evidence they're gathering that suggests it may be an accurate view.

That is my current gripe with the scientific community.. specifically fields like cosmology. I know its hard to gather evidence when you are stuck millions of miles away, but you still need evidence to support hypothesis. If its not testable, or you can't prove it, its not science.

Yes, you would've said the same thing to Albert Einstein in 1905. It's easy to dismiss theories because they are just that: theories. Even so, it's not impossible, but just not the right time or the right technological level to come up with some kind of experiment to test.

The mathematics behind relativity are solid and they are derived from a testable experiment. While I might be inclined to say the conceptual explanation is not completely supported, there is a very clear set of predictable results. I've even personally derived the short version of the Lorentz transformations using 3 dimensions, trigonometry and algebra. If you assume the speed of light is always measured the same, it becomes logically necessary to accept some of the predictions of relativity. So, I definitely would not say Lorentz and Einstein were wrong. In fact, they are quite provable, observable and testable.

Compare that with String theory and the parallel universe theory of quantum mechanics and you see a starkly different picture. Its just an idea. There is no reasonable way to test it, there is no evidence to truly propose the idea to begin with... its just pure philosophy. I can't tell you its certainly wrong, but you have no reason to tell me its right. That is NOT science.

I see some people in here saying "well it may eventually be testable"... but I really haven't seen a good description of what a collision between universes would look like it, or how we would separate such an event from some other unexplained phenomenon... In order for it to be science, you need to have this criteria.

Until such criteria are defined, you have nothing more than a glorified version of Intelligent Design. Despite popular belief, you can make intelligent design be logically consistent with itself. Supporters will ardently claim that evidence could potentially be provided.. You can't straight out disprove gods existence, and you can certainly make an internally consistent claim about how god works.

The difference between things like science and intelligent design, however, is the fact that in science we require evidence before we can truly consider it a viable theory. We also require that it is testable.

Again, its fine to think about how something might work, even when you have no evidence. I do it all the time, and I enjoy philosophy quite a bit. It does bother me though that people start passing things off as "science" when there is no logical basis for their claims.